﻿using System;
using System.Collections.Generic;
using System.Runtime.CompilerServices;
using System.Linq.Expressions;

namespace System.Web.Mvc
{

    /// <summary>
    /// HtmlHelper for My97DatePicker
    /// </summary>
    public static class CalendarExtensions
    {
        private static string defaultFormat = "yyyy-MM-dd";

        /// <summary>
        /// 使用特定的名称生成控件
        /// </summary>
        /// <param name="helper">HtmlHelper对象</param>
        /// <param name="name">控件名称</param>
        /// <returns>Html文本</returns>
        public static string Calendar(this HtmlHelper helper, string name)
        {
            return Calendar(helper, name, defaultFormat);
        }


        /// <summary>
        /// 使用特定的名称生成控件
        /// </summary>
        /// <param name="helper">HtmlHelper对象</param>
        /// <param name="name">控件名称</param>
        /// <param name="format">显示格式</param>
        /// <returns>Html文本</returns>
        public static string Calendar(this HtmlHelper helper, string name, string format)
        {
            return GenerateHtml(name, null, format);

        }

        /// <summary>
        /// 使用特定的名称和初始值生成控件
        /// </summary>
        /// <param name="helper">HtmlHelper对象</param>
        /// <param name="name">控件名称</param>
        /// <param name="date">要显示的日期时间</param>
        /// <returns>Html文本</returns>
        public static string Calendar(this HtmlHelper helper, string name, DateTime date)
        {
            return Calendar(helper, name, date, defaultFormat);
        }

        /// <summary>
        /// 使用特定的名称和初始值生成控件
        /// </summary>
        /// <param name="helper">HtmlHelper对象</param>
        /// <param name="name">控件名称</param>
        /// <param name="date">要显示的日期时间</param>
        /// <param name="format">显示格式</param>
        /// <returns>Html文本</returns>
        public static string Calendar(this HtmlHelper helper, string name, DateTime date, string format)
        {
            return GenerateHtml(name, date, format);
        }

        /// <summary>
        /// 通过lambda表达式生成控件
        /// </summary>
        /// <param name="helper">HtmlHelper对象</param>
        /// <param name="expression">lambda表达式，指定要显示的属性及其所属对象</param>
        /// <returns>Html文本</returns>
        public static string CalendarFor<TModel, TProperty>(this HtmlHelper<TModel> helper, Expression<Func<TModel, TProperty>> expression)
        {
            return CalendarFor(helper, expression, defaultFormat);
        }



        /// <summary>
        /// 通过lambda表达式生成控件
        /// </summary>
        /// <param name="helper">HtmlHelper对象</param>
        /// <param name="expression">lambda表达式，指定要显示的属性及其所属对象</param>
        /// <param name="format">显示格式</param>
        /// <returns>Html文本</returns>
        public static string CalendarFor<TModel, TProperty>(this HtmlHelper<TModel> helper, Expression<Func<TModel, TProperty>> expression, string format)
        {
            string name = ExpressionHelper.GetExpressionText(expression);
            DateTime value;
            object data = ModelMetadata.FromLambdaExpression<TModel, TProperty>(expression, helper.ViewData).Model;

            if (data != null && DateTime.TryParse(data.ToString(), out value))
            {
                return GenerateHtml(name, value, format);
            }
            else
            {
                return GenerateHtml(name, null, format);
            }
        }



        /// <summary>
        /// 通过lambda表达式获取要显示的日期时间
        /// </summary>
        /// <param name="helper">HtmlHelper对象</param>
        /// <param name="expression">lambda表达式，指定要显示的属性及其所属对象</param>
        /// <param name="format">显示格式</param>
        /// <returns>Html文本</returns>
        public static string CalendarDisplayFor<TModel, TProperty>(this HtmlHelper<TModel> helper, Expression<Func<TModel, TProperty>> expression, string format)
        {

            string name = ExpressionHelper.GetExpressionText(expression);

            DateTime value;



            object data = ModelMetadata.FromLambdaExpression<TModel, TProperty>(expression, helper.ViewData).Model;

            if (data != null && DateTime.TryParse(data.ToString(), out value))
            {

                return value.ToString(format);
            }
            else
            {
                return string.Empty;

            }

        }



        /// <summary>
        /// 通过lambda表达式获取要显示的日期时间
        /// </summary>
        /// <param name="helper">HtmlHelper对象</param>
        /// <param name="expression">lambda表达式，指定要显示的属性及其所属对象</param>
        /// <returns>Html文本</returns>
        public static string CalendarDisplayFor<TModel, TProperty>(this HtmlHelper<TModel> helper, Expression<Func<TModel, TProperty>> expression)
        {

            return CalendarDisplayFor(helper, expression, defaultFormat);

        }


        /// <summary>
        /// 生成输入框的Html
        /// </summary>
        /// <param name="name">calendar的名称</param>
        /// <param name="date">calendar的值</param>
        /// <returns>html文本</returns>
        private static string GenerateHtml(string name, DateTime? date, string format)
        {
            if (date != null)
            {
                return "<input type=\"text\" style=\"line-height:25px;height:25px\" id=\"" + name + "\" name=\""+name+"\"  onclick=\"WdatePicker({el:'" + name + "'})\" class=\"Wdate\" value=\"" + date.Value.ToString(format) + "\" />";
            }
            else
            {
                return "<input type=\"text\" style=\"line-height:25px;height:25px\" id=\"" + name + "\"  name=\"" + name + "\" onclick=\"WdatePicker({el:'" + name + "'})\" class=\"Wdate\" value=\"\" />";
            }
        }
    }

}